メタデータ
| 項目 |
値 |
| Designation |
46P/Wirtanen |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-12-12T22:20:53.010240Z |
| Orbit solution date (soln_date, UTC) |
2024-02-21T09:51:41Z |
| Obs used |
4224 |
| NEO |
Yes |
| M1 |
16.600 |
| K1 |
4.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2018-12-13.0000000 |
| e |
0.65875501 |
| q (au) |
1.055355 |
| a (au) |
3.092662 |
| i (deg) |
11.747549 |
| Ω (om, deg) |
82.157634 |
| ω (w, deg) |
356.341072 |
| M (ma, deg) |
0.012474 |
等級
散乱 + 全体線形
$$
M_a = (15.091 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
15.091 |
| n |
2.000 |
| gf |
0.997 |
| gb |
-0.785 |
| k |
1.000 |
| δ90 |
10.000 |
| パラメータ |
記号 |
範囲 |
説明 |
| 太陽・地球距離が1 AUのときの絶対等級 |
H0 |
-5 to 20 |
彗星の固有の明るさ |
| 測光スロープパラメータ |
n |
2 to 6 |
太陽距離に対する明るさ変化率 |
| 前方散乱非対称係数 |
gf |
0.8 to 1 |
前方散乱の強さ |
| 後方散乱非対称係数 |
gb |
-1 to -0.5 |
後方散乱の強さ |
| 分配係数 |
k |
0.8 to 1 |
前方/後方散乱の寄与比 |
| ダスト/ガス明るさ比 |
δ90 |
1 to 10 |
ダスト散乱とガス放射の相対寄与 |
参考: EPSC-DPS2025-160
ファインディングチャート
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
15:58:53.63 |
-18:28:22.2 |
HIP 78219 |
7.32 |
| 2026-09-20 12:00 |
15:59:09.22 |
-18:29:34.9 |
HIP 78219 |
11.06 |
| 2026-09-21 00:00 |
15:59:24.94 |
-18:30:47.9 |
HIP 78219 |
14.91 |
| 2026-09-21 12:00 |
15:59:40.78 |
-18:32:00.9 |
HIP 78314 |
17.20 |
| 2026-09-22 00:00 |
15:59:56.76 |
-18:33:14.2 |
HIP 78314 |
19.46 |
| 2026-09-22 12:00 |
16:00:12.86 |
-18:34:27.6 |
HIP 78314 |
22.23 |
| 2026-09-23 00:00 |
16:00:29.09 |
-18:35:41.1 |
HIP 78454 |
23.24 |
| 2026-09-23 12:00 |
16:00:45.45 |
-18:36:54.8 |
HIP 78454 |
21.14 |
| 2026-09-24 00:00 |
16:01:01.93 |
-18:38:08.6 |
HIP 78454 |
19.67 |
| 2026-09-24 12:00 |
16:01:18.54 |
-18:39:22.6 |
HIP 78454 |
18.99 |
| 2026-09-25 00:00 |
16:01:35.26 |
-18:40:36.7 |
HIP 78454 |
19.20 |
| 2026-09-25 12:00 |
16:01:52.12 |
-18:41:50.9 |
HIP 78454 |
20.29 |
| 2026-09-26 00:00 |
16:02:09.09 |
-18:43:05.2 |
HIP 78454 |
22.14 |
| 2026-09-26 12:00 |
16:02:26.19 |
-18:44:19.7 |
HIP 78454 |
24.60 |
| 2026-09-27 00:00 |
16:02:43.40 |
-18:45:34.2 |
HIP 78454 |
27.52 |
| 2026-09-27 12:00 |
16:03:00.73 |
-18:46:48.9 |
HIP 78704 |
24.07 |
| 2026-09-28 00:00 |
16:03:18.19 |
-18:48:03.7 |
HIP 78704 |
20.79 |
| 2026-09-28 12:00 |
16:03:35.76 |
-18:49:18.6 |
HIP 78704 |
17.95 |
| 2026-09-29 00:00 |
16:03:53.44 |
-18:50:33.5 |
HIP 78704 |
15.79 |
| 2026-09-29 12:00 |
16:04:11.25 |
-18:51:48.6 |
HIP 78704 |
14.66 |
| 2026-09-30 00:00 |
16:04:29.17 |
-18:53:03.8 |
HIP 78704 |
14.80 |
| 2026-09-30 12:00 |
16:04:47.20 |
-18:54:19.0 |
HIP 78836 |
15.90 |
| 2026-10-01 00:00 |
16:05:05.35 |
-18:55:34.4 |
HIP 78836 |
14.15 |
| 2026-10-01 12:00 |
16:05:23.61 |
-18:56:49.8 |
HIP 78836 |
13.69 |
| 2026-10-02 00:00 |
16:05:41.98 |
-18:58:05.3 |
HIP 78836 |
14.68 |
| 2026-10-02 12:00 |
16:06:00.47 |
-18:59:20.8 |
HIP 78836 |
16.88 |
| 2026-10-03 00:00 |
16:06:19.07 |
-19:00:36.4 |
HIP 78836 |
19.90 |
| 2026-10-03 12:00 |
16:06:37.77 |
-19:01:52.1 |
HIP 78885 |
21.80 |
| 2026-10-04 00:00 |
16:06:56.59 |
-19:03:07.8 |
HIP 78885 |
22.24 |
| 2026-10-04 12:00 |
16:07:15.52 |
-19:04:23.6 |
HIP 78885 |
23.60 |
| 2026-10-05 00:00 |
16:07:34.55 |
-19:05:39.4 |
HIP 79124 |
21.64 |
| 2026-10-05 12:00 |
16:07:53.69 |
-19:06:55.3 |
HIP 79124 |
17.80 |
| 2026-10-06 00:00 |
16:08:12.94 |
-19:08:11.2 |
HIP 79124 |
14.46 |
| 2026-10-06 12:00 |
16:08:32.30 |
-19:09:27.2 |
HIP 79124 |
12.08 |
| 2026-10-07 00:00 |
16:08:51.76 |
-19:10:43.2 |
HIP 79124 |
11.28 |
| 2026-10-07 12:00 |
16:09:11.32 |
-19:11:59.2 |
HIP 79124 |
12.43 |
| 2026-10-08 00:00 |
16:09:30.99 |
-19:13:15.2 |
HIP 79156 |
14.37 |
| 2026-10-08 12:00 |
16:09:50.76 |
-19:14:31.3 |
HIP 79156 |
14.70 |
| 2026-10-09 00:00 |
16:10:10.63 |
-19:15:47.3 |
HIP 79156 |
16.53 |
| 2026-10-09 12:00 |
16:10:30.60 |
-19:17:03.4 |
HIP 79156 |
19.44 |
| 2026-10-10 00:00 |
16:10:50.67 |
-19:18:19.5 |
HIP 79374 |
18.76 |
| 2026-10-10 12:00 |
16:11:10.84 |
-19:19:35.6 |
HIP 79374 |
14.06 |
| 2026-10-11 00:00 |
16:11:31.11 |
-19:20:51.7 |
HIP 79374 |
9.57 |